Many bird species, nestlings and immature birds lack external sexual characteristics, making it difficult to identify if a bird is male or female.

But knowledge of a bird’s gender is important, especially for poultry producers who need to know if a turkey is female and therefore worth keeping for reproduction purposes. On the other hand, male turkeys are often slaughtered once their gender is determined so the industry can produce more egg-laying females.

The researchers, who published their findings in the journal Analytical and Bioanalytical Chemistry, used infrared spectroscopic imaging to look at pulp germ cells on the contour feathers of 23 male and 23 female 6-week-old turkeys. Using this method, the researchers accurately guessed the birds' genders more than 95 percent of the time.

The researchers’ hope is that eventually the technology can be used to “determine the gender of germ cells in a fertilized but non-bred egg or to identify non-fertilized eggs under in-ovo conditions,” said Dr. Gerald Steiner, one of the researchers.

In other words, the researchers can determine whether the bird is male or female even the egg has hatched.

Doing this could allow the “breeding industry to select female eggs for breeding and to avoid the killing of millions of male chicks shortly after hatching," said Steiner.